Insect reproduction requires sperm transfer. This project asks about the glands which nourish, package, and transfer sperm between male and female mealworm beetles. The glands mature within a period of 18 days. We ask about the hormones which control their growth and differentiation by culture of these reproductive accessory glands in vitro and in vivo. We are especially concerned with the roles of ecdysone and juvenile hormone in the pupa. In order to monitor the extent of differentiation, we are using gel electrophoresis of leucine-labelled proteins, immunochemical assay of differentiation specific proteins, and in vitro translation of the messenger RNAs.